[DeadArgElim] Strip allocsize attributes when deleting an argument.

Since allocsize refers to the argument number it gets invalidated when
an argument is removed and the numbers shift.

llvm-svn: 328481

1 files changed, 6 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
index 78a2227cde9..3a86c88c98f 100644
--- a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -837,10 +837,14 @@ bool DeadArgumentEliminationPass::RemoveDeadStuffFromFunction(Function *F) {
 
   AttributeSet RetAttrs = AttributeSet::get(F->getContext(), RAttrs);
 
+  // Strip allocsize attributes. They might refer to the deleted arguments.
+  AttributeSet FnAttrs = PAL.getFnAttributes().removeAttribute(
+      F->getContext(), Attribute::AllocSize);
+
   // Reconstruct the AttributesList based on the vector we constructed.
   assert(ArgAttrVec.size() == Params.size());
-  AttributeList NewPAL = AttributeList::get(
-      F->getContext(), PAL.getFnAttributes(), RetAttrs, ArgAttrVec);
+  AttributeList NewPAL =
+      AttributeList::get(F->getContext(), FnAttrs, RetAttrs, ArgAttrVec);
 
   // Create the new function type based on the recomputed parameters.
   FunctionType *NFTy = FunctionType::get(NRetTy, Params, FTy->isVarArg());